At W.C. Machine & Tool, a CAM system that supports Automatic Feature Recognition has reduced toolpath generation time for complex electronics enclosures from a full 8 hour working day to just one hour. Previ-ously, these enclosures took an entire day to program because a great deal of time had to be spent manually selecting all the pockets and specifying their depths. However, the new CAM system’s Automatic Feature Recognition identifies the pockets from the imported solid models and automatically calculates the heights and depths of each pocket and island, eliminating the need to enter this information by hand. "With these tasks now being performed automatically by the CAM system, I can program eight times as many parts per day as I could in the past," says Chris Albrecht, programmer at W.C. Machine & Tool. His increased productivity has allowed the company to increase sales and profits significantly.

W.C. Machine & Tool Inc., Chandler, Arizona, is a "one stop shop" offering custom machining and manufactur-ing, precision sheet metal, and prototyping as well as long and short production runs. Its end-to-end services include CAD/CAM design, CNC and EDM machining, heat treating, sheet metal, grinding, welding, inspection, and more. Having all these disciplines in-house gives the company complete control of projects. Its two-shift operation provides 3,000 hours of shop capacity per month. The company's ability to respond quickly when fast turnaround is required has brought in a great deal of work, allowing the company to grow from five em-ployees to 35 in the last few years.

Limits of ordinary CAMW.C. Machine & Tool has a variety of high-precision CNC machining centers including: Fadal VMC 4020, MilTronics Model P1 S/N2989, Okuma Model MC-4VA, Bridgeport EZTrak, Tree Journeyman, Prototrak 3 Axis Bed mill, and Hardinge Cobra 65. Its EDM center is set up to achieve intricate shapes, punches, and dies as well as high-tolerance production parts on Mitsubishi Wire SX10, Mitsubishi Wire FX 10, Mitsubishi Sinker VX10, and CT300 Small Hole Popper machines.

As the company acquired its CNC machines, it also purchased a CAM system to automate the program-ming of these machines. This previous system saved time, but only on simple parts; the programmer select-ed a start point, indicated the direction of travel, speci-fied tools, feeds, and speeds, and gave the command to create the toolpath. However, complex parts still required a great deal of manual effort to program with the old CAM system. In these parts, geometric features such as bosses, grooves, and holes also had to be selected manually. Then the programmer had to enter machining parameters, such as cutting depth, for each individual feature by hand. Although default parameters were presented, even when they were appropriate, it was still very time consuming to have to go through a complex part and identify every feature.

Some of the electronics enclosures that the company makes are particularly time-consuming in this regard. The enclosures consist of multiple pieces. On the outside, they are solid planes. Their inside surface,

Automatic Feature Recognition Increases Productivity for ETlectronics Enclosure Manufacturing by Eight Fold

Left: electronic enclosure, complex interior surface: Two islands containing numerous subpockets of dif-ferent depths; Right: ESPRIT’s Automatic Feature Recognition identifies and calculates the depths of the pockets and islands in WC’s electronic enclosure used for transceivers.

however, is very complex with numerous pockets and islands that printed circuit boards fit into. The geometry is complicated by the fact that the pockets surrounding the islands are different depths. In the past, these parts could take four to eight hours to program manually be-cause each pocket had to be selected individually and then assigned the correct cutting depth.

Then the company purchased a new CAM system, ES-PRIT, from DP Technology, Camarillo, California. They chose this CAM system because it had been highly rec-ommended by a large customer, Mitsubishi, which also uses the system. ESPRIT utilizes strong feature recog-nition capabilities that greatly simplify the programming of complex parts. ESPRIT's Automatic Feature Recog-nition eliminates the need to manually select individual features such as pockets, islands, holes, bosses, and grooves. The system’s Automatic Feature Recognition identifies them directly from the imported solid, surface, or wireframe models. It also recognizes properties and relationships of part features. "We now select all the features on those complex electronics enclosures with just three mouse clicks," says Albrecht. "What used to take up to eight hours is now done in seconds."

More automated processWith ESPRIT, CNC programming for those electronics enclosures now begins with the import of the custom-er's CAD file in STEP format. Albrecht utilizes the CAM system's Automatic Feature Recognition to highlight all pockets and other features that need to be cut. Then he invokes another automated programming capability of ESPRIT: A pocket machining cycle that automati-cally creates the tool path to cut the pocket utilizing the “Feature” information. This automated machining cycle handles unlimited complexity in both pocket profiles

and number of islands. It can machine through pockets, blind pockets, multi-level bottomed pockets, bosses, wall protrusions, tapers, pockets within pockets, and multiple height islands. Straight and tapered walled pockets and islands, climb and conventional cutting, spiral-out and spiral-in cutting styles, helical, ramp, and zigzag tool entry modes are all supported. Other automated machining cycles are also available. For ex-ample, when a part requires contour cutting of a profile, all cutting depths, cutter compensation, draft angles are automatically calculated.

Once features have been automatically identified and pocket depths have been calculated, the programmer specifies the tools to be used. Tools can be chosen from a tool library or created specifically for each job. Albrecht usually creates them for the particular job because it gives him more control over the machining process. Then he defines feeds and speeds. On the electronics enclosures, he mainly uses the default feeds and speeds that have been set up in ESPRIT for all the different materials. At times, he will adjust the speeds to suit the tool, such as when he wants a smaller or large end mill than is normally used. "Otherwise, ESPRIT automatically makes these selections and it works very well," says Albrecht.

The next step is generating the toolpaths. This pro-cess is done through a single command window. In the window, Albrecht enters clearance values and then gives the command to create the toolpaths. Before giv-ing the command to generate the G-code, he views a simulation of the toolpaths on the screen. "The simula-tion shows the removal of material from a solid model," Albrecht explains. "I look at it to make sure it's cutting just what I want."

Left: WC Machine & Tool utilizes a variety of high-precision CNC machining centers. Shown is the Fadal VMC 4020 used to machine electronic enclosures; Right: Final Product: WC’s electronic enclosure, as machined

The total programming process for a typical enclosure now takes 30 to 60 minutes, down from an entire day before WC had a new CAM system with Automatic Feature Recognition and advanced pocket machining cycles. The time savings made possible by these two new automated capabilities enable Albrecht to program eight times as many parts per day as he could in the past.

Many of the parts that W.C. Machine & Tool makes are manufactured on both a milling machine and a wire-EDM machine. Wire machines are used for areas with tight tolerances and very small radii. To program these machines, the company uses ESPRIT’s wire-EDM system which also offers Automatic Feature Recogni-tion. Since the areas done on the wire machines usually require only two-axis machining, there are no depths to specify. "We first do the Automatic Feature Recogni-tion, then define which areas are to be done on the wire machine," says Albrecht. "That is about all it takes to program these parts."

W.C. Machine & Tool has grown quickly in the last few years and kept up with a large increase in work volume, in part because it can offer fast turn around. Automatic Feature Recognition and other automated NC program-ming capabilities are making it possible for W.C. Ma-chine & Tool to create toolpaths for complex electronics enclosures in only one hour. Because the programmer no longer spends time manually selecting features and specifying machining parameters, his productivity has increased by a factor of eight. Another asset that wins business for W.C. Machine & Tool is its very competi-tive pricing. Here, too, the CAM system plays a role. "Because we can program fast and don’t need to hire additional programmers to do the jobs, we can charge less," says Albrecht.

For further information contact DP Technology Corp., 1150 Avenida Acaso, Camarillo, California 93012. Telephone: 805-388-6000;Fax: 805-388-3085; Website: www.dptechnology.com